The Japanese electronics giant confirmed it had received a subpoena from the DoJ seeking information about Sony's SRAM business. The DoJ has already issued similar subpoenas to Samsung, Mitsubishi, Toshiba and Cypress Semiconductor.

While not confirming specific subpoenas, a DoJ spokesman told internetnews.com, "The antitrust division [of the DoJ] is investigating the possibility of anticompetitive practices in the SRAM industry."

SRAM is a faster, though more expensive, type of computer memory than dynamic random access memory (DRAM) used in personal computers, disk drives and networking equipment.

In a brief statement, Sony said it "intends to cooperate fully with the DoJ in what appears to be an industry-wide inquiry."

The other companies issued subpoenas have also pledged to cooperate with the investigation.

The new SRAM antitrust probe follows the DoJ's ongoing two-year investigation into price fixing in the DRAM chip industry.

To date, the probe has resulted in Korean-based Samsung and Hynix, Japan's Elpida and Infineon of Germany pleading guilty. The companies have paid a combined $729 million in criminal fines.

In addition, 13 former executives from the four companies and a former executive from U.S.-based Micron have pleaded guilty to conspiracy charges. All have been fined and sentenced to prison terms.

Earlier this month, a San Francisco grand jury indicted two more former Samsung executives and a Hynix official in the investigation. If convicted, all three face maximum jail terms of three years and fines of $350,000 each.

Sony's possible involvement in an antitrust investigation adds to the company's growing list of woes.

Last summer, computer makers including Apple, Dell, Lenovo, Toshiba and Panasonic all announced product recalls in the millions because of faulty, overheating Sony lithium-ion batteries installed in their machines.

In addition, Sony has delayed the launch and reduced the shipment goals of its next generation PlayStation 3 console.

The worldwide battery recalls and the delayed PlayStation launch led to a 94 percent drop in profits for Sony in the third quarter.